The present invention concerns a fastener for fastening together the ends of a length of steel strap wrapped around a package in a package strapper. It has a top and a bottom. The top is above the section of a track where the fastening is established. The bottom is below the same section. The top is accommodated in a housing that pivots on the bottom on a hinge paralleling the track. The top comprises strap-shaping punches, a strap clamp, and a strap cutter. The bottom comprises a strap-shaping die mounted on a base and facing the punches.
The base in conventional package strappers is between the fastening and the package. It must accordingly be extracted to one side in order to release the package for removal. Extracting and re-inserting just the base renders the incision less precise due to wear and tear on the guides or dirt on the strap stops. The imprecision enlarges the nip between the punches and the die, which rapidly wears the punches out. This drawback is eliminated in known designs by mounting the strap punches and the die on a part of the housing that can be pivoted away from the track such that the punches and die remain in the same relative position even while the housing is being pivoted away.
One drawback to positioning the punches and die on the same pivoting housing is that it complicates the mechanism driving the punches in the strap clamping-and-cutting mechanism, which must be divided or separated while pivoting.